Notes, summaries, assignments, exams, and problems for Geology

Sources of Petroleum

Petroleum originates from a small fraction of the organic matter deposited in sedimentary environments.

“Source Rock”

The typical “source rock” contains 99% mineral matter and 1% organic matter. The organic matter is composed of 90% kerogen and 10% bitumens.

This organic matter is usually a combination of marine- and terrestrially-derived organic matter (plant) and zooplankton (animal), which constitutes more than 95% of the life in the oceans.

Terrestrial organisms are mainly wind-blown spores and pollen, along with some woody debris from rivers and swamps.

All living matter is composed of four main constituents: lipids, proteins, carbohydrates, and lignins.

Kerogen Types

1. Type I Kerogen

This type of kerogen has a high... Continue reading "Petroleum Sources: Kerogen Types and Their Significance" »

Biodiversity

Biodiversity = Number, variety and variability of Earth’s organisms (of plants and animals)

Levels of Biodiversity

1. Genetic Diversity - The genetic variety within all populations of that species.

2. Species Richness - The number of species

3. Ecosystem Diversity - The variety of ecosystem found on earth. Ex, The forests, prairies, deserts, coral reefs, lakes

Endangerment and Extinction

Species of imminent danger of extinction throughout all or a significant portion of its range.

The death of the last individual of a species.

Leading Causes of Endangerment and Extinction

• -land use of biodiversity hotspots(biggest contributor to species loss)
• -The introduction of a foreign species into an ecosystem from  which it did not evolve.
• -Overexploitation:

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The Composition and Classification of Rocks

Rock is any natural, inorganic material made up of one or more minerals. Rock forms the solid part of the Earth's crust.

Rocks formed of only one type of mineral are called mono-mineralic rocks, but rocks are usually formed of more than one mineral.

Exceptions to the Definition

There are two notable exceptions often referred to as 'rocks':

• Oil: Considered a liquid 'rock'.
• Coal: Formed from the remains of plants (organic material).

The Three Main Types of Rocks

Rocks are classified into three primary types based on their formation process:

1. Igneous Rocks: Rocks formed when magma cools and solidifies. (Magma is molten rock.)
2. Sedimentary Rocks: Rocks formed by the accumulation and cementation of fragments of other

Understanding Major Pollution Types and Mitigation Strategies

Air Pollution: Effects and Solutions

Effects of Air Pollution

• Acidification: Chemical reactions involving air pollutants create acidic compounds that harm vegetation and buildings.
• Eutrophication: Rain carries and deposits nitrogen from pollutants onto rivers and soils.
• Ground-level Ozone: Chemical reactions involving air pollutants create ozone, a poisonous gas.
• Particulate Matter: Air pollutants in this form are highly detrimental to human health.

Preventing Air Pollution

Government and Community Level Prevention

• Using renewable green energy sources (e.g., wind, solar).
• Enforcing regulations that compel companies to control the pollution they cause.
• Promoting the use of energy-efficient vehicles.

Isostasy: Lithosphere–Asthenosphere Equilibrium

Isostasy: The equilibrium between the lithosphere and the underlying asthenosphere.

Studying the Ocean Floor

Studying the ocean floor

Echo sounders produce sound waves that travel outward in all directions. The sound waves bounce off the nearest object and then return to the ship. Scientists know the speed of sound in seawater; they can then calculate the distance to the object that the sound wave hit.

Marine Sediment and Pillow Lavas

Marine sediment: very thin. Pillow lavas: volcanic rocks, very young compared with continental rocks.

Antarctic Ocean Floor Features

• Continental shelf: the edge of the continent that lies underwater.
• Continental slope: the area between the continental shelf and the abyssal

Types of Plate Boundaries

1) Constructive or Divergent Boundaries

Two plates move apart from each other. New magma rises to the surface, cools, and forms basalt, creating volcanoes and rift valleys.

2) Destructive or Convergent Boundaries

Two plates move towards each other. Typically, an oceanic plate sinks below the other in a subduction zone. Sediments between the plates fold, forming mountain ranges. Friction melts rocks, causing volcanoes and earthquakes.

3) Conservative Boundaries

Two plates slide against each other, often at different speeds. Stress buildup leads to sudden movements and friction, resulting in earthquakes.

Negative Impacts on People

Earthquakes

Earthquake shockwaves damage buildings, bridges, and roads, causing injuries and fatalities.... Continue reading "Understanding Plate Boundaries and Their Impact" »

Composition of Earth's Atmosphere

• Nitrogen (78%)
• Oxygen (20%)
• Argon (1%)

Greenhouse Gases

Examples: H2O, CO2, CH4, NO2, O3

Importance: Without greenhouse gases, Earth's temperature would be -22 to -36 degrees Celsius.

Greenhouse Effect

Solar energy absorbed by Earth and re-radiated as heat by greenhouse gases.

1. Natural Greenhouse Effect
2. Human-Induced Greenhouse Effect (Global Warming)

Global Warming / Climate Change

Caused by burning fossil fuels, deforestation, and human activities that increase carbon dioxide levels, leading to Earth's warming.

Ozone, Hole in Ozone, UV Rays, CFCs

Ozone

Located mostly in the lower stratosphere, it acts as a shield against harmful UV radiation from the sun.

Hole in the Ozone Layer

Causes: Primarily caused by human-made chemicals... Continue reading "Understanding Earth's Atmosphere and Climate Change" »

Coastal Erosion

Factors Influencing Wave Size and Energy

The size and energy of a wave are influenced by:

• How long the wind has been blowing
• The strength of the wind
• The fetch (the distance the wind blows over the surface of the water)

Rate of Coastline Erosion

The rate of coastline erosion is influenced by:

• Type of rock (e.g., chalk and limestone form steep cliffs)
• Strength of waves
• Speed of waves

Destructive Waves

Destructive waves are created in storm conditions. They are characterized by:

• Being created from big, strong waves when the wind is powerful and has been blowing for a long time
• Occurring when wave energy is high and the wave has traveled over a long fetch
• Eroding the coast
• Having a stronger backwash than swash
• Having a short wavelength and being

Volcanoes

Scenario: Consider a geographic location for a volcano. What type of plate setting is it located in? What kind of volcano is it (composite, dome, or shield)? What kind of lava does it produce (rhyolite, andesite, or basalt)? Is the lava predominantly silicate, feldspar, or ferromagnesian? Why? Is the lava felsic, mafic, or a combination in origin? Why? Describe the characteristics of a volcanic eruption.

Plate Tectonics:

• Divergent (mid-ocean ridges = volcanoes)
• Rift zones = volcanoes
• Subduction zones = volcanoes
• Hot spots = volcanoes

Lava

Composition:

• Result of the geologic setting, which determines available source material.
• Extent of melting, which determines what becomes the source material.
• A mix of SiO4, Al, Fe, Mg.

• Rich in SiO4: more felsic